In a multi-node system, nodes may appear as a single system to application servers and user applications. Each node may handle its share of the workload during the normal operation when all the nodes in the multi-node system supposed to be up are in fact up. When one of the nodes fails (or is out of service for whatever reason), a particular node may be required to take over some, or all, of the failed node's share of the workload.
Unfortunately, the takeover (or failover) node may have used its capacity for its own share of the workload to such an extent that the node can hardly take over the failed node's share of the workload. For example, the takeover node may already use 60% of CPU time for processing its own share of the workload. Servicing the failed node's share of the workload may require more than 40% of additional CPU time. Thus, when the failed node's share of the workload is over flown to the takeover node, the takeover node does not have sufficient CPU time for processing both its own share and the failed node's share of the workload. This may cause the takeover node to fail.
This situation may be worsened, because the application servers and user applications that initiate the workload may not be aware of the fact that one or more nodes of the multi-node system are out of service. In fact, it may appear to the application servers and user applications that the multi-node system is handling an ever smaller number of transactions than before. The application servers and user applications may increase the number of requests sent to the multi-node system. As a result, more nodes in the multi-node system may fail.
As clearly shown, techniques are needed for dynamically monitoring and managing resource usages of processes in computer systems.
The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section.